At present, the mainstream technologies in the flat panel display industry are LCD (Liquid Crystal Display) and OLED (Organic Light-Emitting Diode). The OLED is more flexible than LCD and can diversify the display forms.
The TFT (thin film transistor) substrate of the OLED adopts a flexible board as a substrate to dispose TFTs. Then, the OLED light emitting layer, the TFT package layer, the polarizer and the glass cover plate are sequentially arranged on the TFT substrate. The outer lead region is arranged on the same side of the substrate where the TFT substrate is configured. The outer lead region is used to arrange the driving chip, the flexible circuit board for connection and to arrange the metal trace layers of the OLED light emitting layer and the chip circuit board. At present, the main way to realize the flexibility is to bend the portion of the substrate having the outer lead region to the back side of the entire TFT substrate. Accordingly, the metal trace layer must be bent, together. The metal trace layer after being bent is in a bent state and suffers a certain stress. The bending stress of the substrate is larger and the metal trace layer can be easily broken as being bent with the substrate, together.